Enhanced heat transfer surfaces are used in many cooling applications, for example, in the HVAC industry, for refrigeration and appliances, in cooling of electronics, in the power generation industry, and in the petrochemical, refining and chemical processing industries. Enhanced heat transfer tubes for condensation and evaporation type heat exchangers have a high heat transfer coefficient. The tube surface of the present disclosure comprises a surface ideal for use as a condenser tube, while additional steps in the method of forming the tube will result in a surface ideal for use as an evaporator tube.
A method for forming features in an exterior surface of a heat transfer tube according to the present disclosure comprises forming a plurality of channels into the surface, where the channels are substantially parallel to one another and extend at a first angle to a longitudinal axis to the tube. A plurality of cuts are made into the surface, the cuts substantially parallel to one another and extending at a second angle to a longitudinal axis to the tube, the second angle different from the first angle. The cutting step forms individual fin segments extending from the surface, the fin segments separated from one another by the channels and the cuts. The fin segments comprise a first channel-adjacent edge adjacent substantially parallel to the channel, a first cut-adjacent edge substantially parallel to the cut, and a corner formed by a second channel-adjacent edge and a second cut-adjacent edge, the corner rising upward from a channel floor and partially extending into the channel. A tube formed using this method has excellent qualities for use as a condenser tube.
Additional steps in the method will result in an excellent evaporator tube. Following the cutting step discussed above, the fin segments are compressed with a roller, causing an edge of the fin segments to bend at least partially over the cuts. The step of compressing the fin segments further causes an edge of the fin segments to extend at least partially over the channels.
For purposes of summarizing the invention, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any one particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.